Delete dead code in cluster_manager.

controllers/gce/controller/cluster_manager.go

@@ -17,7 +17,6 @@ limitations under the License.
 package controller
 
 import (
-	"fmt"
 	"io"
 	"net/http"
 	"os"
@@ -39,10 +38,6 @@ const (
 	defaultPort            = 80
 	defaultHealthCheckPath = "/"
 
-	// A single instance-group is created per cluster manager.
-	// Tagged with the name of the controller.
-	instanceGroupPrefix = "k8s-ig"
-
 	// A backend is created per nodePort, tagged with the nodeport.
 	// This allows sharing of backends across loadbalancers.
 	backendPrefix = "k8s-be"
@@ -199,10 +194,6 @@ func (c *ClusterManager) GC(lbNames []string, nodePorts []int64) error {
 	return nil
 }
 
-func defaultInstanceGroupName(clusterName string) string {
-	return fmt.Sprintf("%v-%v", instanceGroupPrefix, clusterName)
-}
-
 func getGCEClient(config io.Reader) *gce.GCECloud {
 	// Creating the cloud interface involves resolving the metadata server to get
 	// an oauth token. If this fails, the token provider assumes it's not on GCE.